


Chemicals

by zaffrin



Category: Doctor Who (2005)
Genre: Alpha Master, Alpha/Beta/Omega Dynamics, Alpha/Omega, Alternate Universe - Modern Setting, Childhood Friends, Dom/sub Undertones, Enemies to Lovers, F/M, Knotting, Mating, Mating Bites, Mating Bond, Mating Cycles/In Heat, Omega Verse, Smut
Language: English
Status: Completed
Published: 2020-08-21
Updated: 2020-08-28
Packaged: 2021-03-07 02:07:55
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 19,159
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26029201
Author URL: https://archiveofourown.org/users/zaffrin/pseuds/zaffrin
Summary: Due to the prejudice against Omegas, Theta had hidden her designation when she'd applied to work at the Gallifrey Research Facility. Only Koschei, who she grew up with (and who also now happens to be her boss - as well as an Alpha) knows she isn't a Beta. He's the only one who can help her when she forgets to take her suppressant and goes into heat at work, but with their complicated past, things are not straightforward for either of them...
Relationships: Thirteenth Doctor/The Master (Dhawan)
Comments: 109
Kudos: 165





	1. Chapter 1

**Author's Note:**

> Hi! This is an Alpha, Beta, Omega fic, where the Doctor is an Omega and the Master is an Alpha. If you’re not familiar with omega-verse but still want to read it, it should still be accessible and make sense, I’ve included some explanations in the story. Its going to be a little weird though if it’s new to you so just a heads up about that! Take care to read the tags.
> 
> Anyway this was meant to be PWP but apparently I need a little backstory and drama with my smut so here we are 15k and 3 chapters later. Hope you don't mind. And hope you enjoy if you do decide to read! :P

When Theta had applied to the Gallifrey Research Facility fresh out of studying for her PhD, she’d never really expected to get the job. 

It was a notoriously difficult company to get into, and she was sure they’d be dozens, if not hundreds of other applicants with more experience than her. That’s why, when she’d checked the box for ‘Beta’ under designation on her application, she hadn’t thought anything of it. It was an Alpha-led company. And while the law dictated that no discrimination must take place against designation during hiring, the fact that companies were still allowed to demand to know on application forms debunked that. They’d always just say the other applicant was the better fit. Theta knew - had always known, that as an Omega she would be treated differently throughout life, and she refused to let it impact her career and her goals. She was good - she  _ knew _ she was good, so as soon as she’d got her PhD in biochemistry, she’d decided that she simply would not allow her designation to hold her back. 

So. She’d checked the box for Beta. She’d impressed them in her interview, and gotten the job. And it had been fine. She’d gone on the strongest kind of suppressants she could get her hands on, and used scent block spray every morning. Nobody knew she wasn’t the Beta she claimed to be. 

Except for Koschei. 

When Theta had walked into the office on her first day, and been introduced to her new floor manager, she’d almost turned and run back out.

It was  _ him _ . 

Koschei, who she’d gone to school with. Koschei, her first friend on her very first day and her best friend for years after. Koschei, who she’d -

She’d swallowed, hard, refusing to let herself think about  _ that  _ on her first day at her first proper job, refusing to let  _ him _ mess this up for her, and stuck out her hand like this was a first meeting. 

He’d taken it, and shaken it politely, but his eyes had held hers until she was led away, and it was only an hour until her new laptop pinged with an IM from the companies internal system she’d just been set up on. 

**Koschei: Wasn’t aware we were hiring Omegas in this department now.**

Theta had ground her teeth and fought the urge to tell him to piss off. Instead, she knew she had to address it; Koschei could ruin everything for her. 

**Theta: I’m a Beta.**

**Koschei: No, you are not. I think I should know.**

Theta had flushed red right there in front of her screen.  _ Damn him.  _

**Theta: Koschei, please. I can do this.**

**Koschei: Job? Yes, of course you can. But hide your designation? That’s ridiculous. Half the department are Alphas.**

**Theta: I’m on suppressants. And scent blockers. It will be fine.**

It was several minutes until she got a reply to that one, and Theta passed the time nervously biting her nails, watching that little typing bubble with a hammering heart. 

**Koschei: Your funeral.**

She’d breathed out a sigh of relief. 

**Koschei: Delete these messages. I will too. Don’t blame me if you find yourself in trouble.**

**Theta: Thank you. It will be fine.**

And it was. Fine - it had been. Theta had worked at Gallifrey for nearly a year now, and as far as everyone was concerned, she was just a normal Beta. Things may be complicated between her and Koschei, and they weren’t exactly on friendly terms, but he had kept her secret. Mostly, she tried to keep out of his way. He was technically her boss, which meant it wasn’t always possible, and she was forced to be polite to him in the weekly staff meetings, but he was… difficult, at best, to work with. He always had been arrogant and short-tempered - towards the end of their time at school together anyway. A typical Alpha, who walked around thinking he was above most other people just because of his designation - just because he was large and strong and could knot an Omega. It was stupid. It didn’t mean anything, even if Alphas did think they ruled society and that Omegas were generally just around to do their bidding, bear their children and keep them happy. 

Theta was here, proving that that was wrong right now, wasn’t she? Gallifrey was the top research company in the medical field, and Theta had excelled in her first year here. 

She hadn’t been surprised that she and Koschei had ended up going into the same field - they had always studied together in school, and always liked the same subjects, before… things changed. She was however, surprised to find him in a manager’s position when they were same age and she had got her doctorate in record time. 

She found out one night a few months in, working late, when she realised he and she were the only ones left in the office and curiosity got the best of her. 

“Was there anything else?” He looked up from his desk impatiently when Theta hovered at his door after dropping the new vaccine samples she’d created in.

She frowned. “How are you here?”

“Excuse me?”

She waved a hand. “Here - in the manager’s chair already. Did you murder someone and take their job?”

He snorted, tossing his pen to the table. “I’m offended that you think I couldn’t have done it on merit alone.”

“But how? I just got my doctorate - and I was fast. The first to graduate in my university, even if you skipped the PhD, you can’t possibly have -”

“I didn’t go.”

She’d blinked at that. “What?”

“Nope. Got an apprenticeship here straight after school. Organising the lab samples to start with - cleaning up the spills. I worked my way up.”

Theta had leaned against the doorframe and folded her arms, impressed. “Wow,” she’d said, a genuine smile on her lips for him for the first time since she’d started. 

He had smirked back. “It helps that half the assistants are scared of me. They quickly realised I could work best in a position of authority.”

The smile dropped from Theta’s face and she rolled her eyes. “You are so arrogant. Haven’t changed, have you?” She’d shot at him bitterly. 

“And you still think you’re better than everyone else,” Koschei shot back, and Theta narrowed her eyes and whirled on her heel to leave before she threw something at him.    
“Theta,” his low voice made her halt. She  _ hated it _ . Hated that something deep within her forced her to obey his demand, made her turn and look at him again rather than march out of there like she wanted to. 

He wrinkled his nose. “You might want to switch your scent block. You reek of Omega from over here.”

Her whole face had flushed red, and she’d only been able to splutter for a moment before she found her voice. 

“I’m - I don’t usually work this late,” she ground out, “It’s just worn off is all, there’s nothing wrong with it!”

“Sure,” he’d commented, already shuffling with papers on his desk like he’d lost interest in the conversation. 

“There isn’t! I’d usually be home by now, and nobody else is here so -”

“I get it,” he’d said dryly, then lifted a handkerchief to his nose and mouth. Theta knew her scent likely  _ was _ spiking with her irritation, but the gesture just proceeded to make anger and embarrassment - and consequently more anger - roll off her in waves. She’d turned on her heel and stormed out, slamming the door of his office so hard it rattled on its hinges. They hadn’t spoken for a month. 

She hated Koschei. She  _ hated him _ . Him and his arrogant air, his stupid floppy dark hair and eyes that looked like they could pierce right into her soul. It didn’t matter that he smelled delicious - she was an Omega, and any Alpha smelled good to her. Well. That wasn’t  _ quite _ true, there were certainly some scents that were more appealing than others, and Koschei’s just happened to be especially to her taste but… - that wasn’t her fault. That wasn’t something she could help. That was just pheromones; chemicals. The same thing that had driven her teenage self to beg for what she never should have had when her first heat had hit. And the same thing causing that strange emptiness inside her whenever she thought of what had happened after and since. 

Typically, people’s designations presented themselves at around age eighteen - sometimes even as late as twenty one or two. But there were exceptions… Theta had been one of the exceptions. And so had Koschei. 

They used to be friends - best friends, all through school. It was a prestigious academy that focused on the sciences, that little orphan Theta had got herself into on a full scholarship when her previous school had realised she was exceptionally bright for an eight-year-old. Koschei already attended, and he’d grinned at her on her first day when she’d been nervous as hell, and offered her the seat next to his in class, then shared his packet of humbugs with her at break. They were friends ever since. 

But then they grew older and her first heat had hit at the same time as his rut. Maybe she’d triggered it - or he’d triggered hers… either way, they were very young, her barely fifteen and him just six months older and while they  _ knew _ what they were doing they didn’t really know what they were doing, not enough to stop biology and hormones taking over their senses completely as they’d shed clothes and come together. He’d knotted her right there, at the back of their school playing field behind some bushes, and when she’d bared her neck to him, high on sex and pheromones, soft pleas falling from her lips, begging him to claim her and make her his, he’d bitten into her mating gland without a second thought. 

Borosa, their head had found them, newly mated and still knotted, and Theta will never get over the shame she’d felt that day. Koschei had pulled out of her in a blind panic and there’d be blood, and her scream and Borosa’s voice as he’d yelled for help… the rest was a blur. Koschei had been sent home to his parents and Theta, with no home to go to, had spent the next three days of her first heat locked in her room, shaking and feverish, crying brokenly for her missing mate.

The academy doctor had injected her with something, she didn’t know what it was at the time but had it explained to her afterwards when her senses had returned that it was something like the morning after pill - preventing not only a pregnancy occurring but also, if given within twelve hours of a mating bite, reversed the effects of the bond. 

By the time Koschei came back to school, the mark on her neck was nothing but a scab. Just a scab. 

Things had never been the same between them after that. Koschei could barely stand to be around her, and everytime Theta looked at him she couldn’t help but remember the heat of his strong form against hers, the fullness of his knot inside and his teeth on her neck… but mostly she remembered the sheer agony of being ripped from him, of the coldness in his eyes the next time she had seen him and his gaze had landed on her neck, when all she’d wanted was for him to take her in his arms and tell her everything was okay. 

Theta had never taken another knot since - she couldn’t. Too many painful memories were tied to it for her to even consider laying with another Alpha again. Sure, she’d been with a few Betas, and even another Omega once, but never another Alpha. Never again. 

That was in the past now. A decade ago. Theta would always carry a part of it with her - in a way it had shaped who she had become - who she’d  _ made _ herself become. Independent, and determined to rely on nobody but herself, despite her stupid designation and the ideas society had for her. Her biology existed, and she couldn’t escape that, but she was a scientist and she knew that when she had her heats and was completely taken control of by hormones that that was just what it was: hormones. Chemicals in her brain. It didn’t matter that fifteen year old Theta had adored her best friend - when she’d asked him to bite her it had just been her Omega talking, hormones running wild, both of them too young and inexperienced to know how to control them. And it was his Alpha that gave over to instinct and did it, not Koschei himself. It hadn’t been what he truly wanted; that was clear from the way he acted afterwards. And when she was forced to consider it afterwards, it wasn’t what she wanted either. It would have been insane, to be mate bonded to someone so young. It didn’t matter that a part of her still mourned for that brief connection, that a part of her ached for loss of Koschei every day… that wasn’t Theta. It was just chemicals.

And so. What happened hadn’t held her back, if anything it had given her even more drive to make something of herself and her life  _ by  _ herself. And now she was here, with a promising career laid out ahead of her and having to put up with Koschei was just a small part of a job she otherwise loved. She could handle him. Even if he did seem determined to berate her at every possible opportunity. That was when he wasn’t point black ignoring her. 

Unfortunately, it looked like today was going to be one of the former days, when Theta glances up from her desk where she’s typing up a report and sees him making a beeline for her from his little office in the corner. Great. It’s not like she hadn’t already had the  _ worst  _ morning - she’d overslept, forgetting to set her alarm and consequently had to skip breakfast and a shower, couldn’t get a seat on the tube, ran into three people in her mad dash to get to work on time and still missed the start of the morning meeting. She curses under her breath as Koschei approaches. 

“Doctor,” he says, his voice low but urgent, despite the formal way he addresses her. “A word in my office.”

“I’ll be right in,” she replies, not looking up from her screen. “Just need to finish -“

“ _ Now,” _ he growls, turning without waiting for her answer and stalking off.

Huffing irritably, and rolling her eyes at her co-worker’s teasingly muttered, “someone’s in trouble,” Theta pushes her chair back and gets to her feet, crossing the floor to her boss’s office. She enters without knocking to find him pacing. He motions for her to shut the door and she does so.

“What do you need, Koschei?” She says, more than a bit annoyed, “I was in the middle of something and I’m going to lose -“

“Did you forget your suppressants?”

She blinks at the question. That hadn’t been what she expected to hear  _ at all. _

“No! Of course I didn’t, I take them every morning just after I -“ she cuts off, remembering her manic morning. “ _ Shit.”  _ She grabs her shirt, giving it a sniff.

“Shit,” Koschei repeats. He tears away from her to drag down the blinds around his office windows, locking the door and turning back to her with wild eyes. “We’ve got to get you out of here,” he says urgently.

“What? I can’t just leave, I have a lab this afternoon-“

“And a whole damn office full of Alphas! Don’t be ridiculous Theta, they’d scent you in a second - it was nearly knocking me out from across the room!”

Her brow furrows. “Well nobody else seems to have noticed yet.”

She snaps her mouth shut, realising the implication of her words as soon as they’ve left her lips. Koschei has scented her heat before anyone else had - before she’d even realised it herself.  _ It’s because he’s mated you,  _ her treacherous mind tells her,  _ it’s because you’re already his - _

“I’ll just - I’ll just run home and take one now,” She quickly says to drown out the voice before it can become any louder. 

He snorts. “Yeah - no, it’s too late for that.”

He’s right, she knows he is. She can feel her heat approaching now, feel herself growing warm and a steady ache starting in her belly, a dull throb already beginning between her legs.

“Shit,” she curses for the second time. She runs a stressed hand through her hair and rubs at her neck subconsciously until she realises her mating gland has started to itch, and quickly pulls her hand away. Koschei’s eyes follow it, lingering on her neck. It throbs. Fuck - she’s never had a heat come on this fast before. “You’re right,” she admits, mentally resigning herself to the prospect of having to go through a heat. They were never pleasant experiences, and she’d have to feign off work as being sick because it wasn’t like she could use heat leave as a ‘Beta’, and she hated lying, and she’d get behind on all her labs and -

Koschei clears his throat from across the room, cutting short her internal, slightly panicked monologue. “Do you have - um. Someone to help you? Through your heat.”

She blinks, shaking her head dumbly. “No. It’s fine. I’ve always gone through them alone.”  _ Well… almost always. _ “I’ll be fine. I haven’t had one in over a year but… I’ll be fine,” she repeats. Koschei’s eyebrows shoot up.

“A  _ year?” _

“I’ve been taking suppressants the whole time I’ve worked here,” she says like it’s obvious. It is, isn’t it?

“Jesus Christ Theta, do you know how hard this heat is gonna hit you? A  _ year.  _ Fuck - you’re not supposed to take them for that long without a break!”

She frowns. “How do you know?”

“ _ Everyone  _ who knows anything about them knows that - you should know that.” She frowns, looking away. Her doctor had mumbled something about breaks when he’d given this particularly strong dose to her, but in all honesty Theta hadn’t really been listening. She’d been so caught up in her career that it hadn’t even been something she’d thought about in the last year. 

“Okay,” Theta says, “well… I’m sure I’ll manage. I’ll try and finish up early today so I can get home and -“

“What?” He almost laughs. “Are you serious? You have to get out of here  _ now.  _ Go home right now, I’ll tell them you’re sick.”

She frowns, affronted at this arrogant Alpha thinking he can order her around. “Dont be ridiculous, I’ve got scent blocker in my bag - I can manage the rest of the day, Koschei.”

“No,” he grinds out, “you cannot.”

She stands her ground, folding her arms. “You don’t know what I can and can’t do.”

“I’m just telling you,” he growls. “in a few hours you’ll be begging any Alpha in a mile radius to fuck you.”

“I will not!” She splutters, affronted. “I can keep control through my heats thank you very much.”

“Not a heat like this you won’t be able to.”

“I -“

“You probably shouldn’t even use public transport, it’s not safe. I’ll take you home. Now.”

“I need to finish -“

“No you need to get home right now and barricade yourself in your damn apartment - with me on the other side of the door unless you want to find yourself fucked senseless for the next three days -  _ fuck  _ \- I can barely stop myself jumping you right now,” he drags a shaking hand down over his face, and Theta, stunned by his words, notices that there’s a light sheen of sweat on his brow. Her eyes jump unbidden to his crotch.

“Are you in rut?” It’s a personal question, one she has no right to ask Koschei, but Theta suddenly cannot tear her eyes from him, cannot help but think of him - his hands and his cock, his big strong body pinning hers to the wall, or bending her over that desk of his maybe, ripping off her slacks and pulling her soaked panties down, filling her up as she mewls in delight -

“Not yet,” he grunts, snapping her out of fantasies she has no business indulging in, and shrugs out of his jacket. “Here,” he says, tossing it to her, “put this on. It should help mask your scent at least while we get through the building.”

Head a little fuzzy and underwear growing rapidly damper, Theta nods. “Yes Alpha.”

It’s slipped out before she can stop it, and they both freeze, Theta’s face going bright red. “Um -“

“You can keep control, can you?” Koschei mocks.

“Shut up.”

After throwing open a desk draw and grabbing a small bottle from which he throws back a couple of pills - blockers, Theta realises - Koschei takes her arm and hurries her out of his office. He mutters something to the receptionist on the front desk that Theta doesn’t take in, too wrapped up in sensations of his strong hand wrapped around her arm and the heady scent of him engulfing her. 

The walk down to the parking lot passes in a blur. The cramps are starting already, and Theta moans as she clings to him, her knuckles white where she clutches a fistful of his sleeve.

“Not far,” he murmurs to her lowly, arm tight around her shoulders. She chooses not to comment on the fact that usually they can’t say two nice words to each other, just sincerely grateful for his help in this moment. “You’re alright, I’ve got you.”  _ Alpha’s got you,  _ Theta’s hindbrain repeats contentedly,  _ Alpha will take care of you.  _

He slides into the car next to her after depositing her in his passenger seat, and Theta curls up against the door, pressing her burning forehead to the cool glass of the window as Koschei pulls out of the parking lot at breakneck speed.

“Home,” she rasps out the plea. Despite herself, panic is starting to rise inside her as she feels herself losing her senses, the heady rush of chemicals in her brain expanding and taking over, shooting through her body, making her sweat and gasp and press her thighs together as she feels herself grow slick. 

“I’m taking you there. You’ll be home soon,” Koschei promises, and Theta nods. She just hopes she can keep control of herself until she gets there - and gets Koschei, who is starting to smell better and better as the minutes tick by, away from her in time. 

\--

**Notes for the Chapter:**

> There are two more (very very smutty) parts to this, if people are interested. Let me know if I should continue!? I know it's a bit of a different one… 😅
> 
> And if you have any questions about the fic and the whole omegaverse thing, I’m happy to try and answer them in the comments! (I’m no expert on the whole thing, it’s still quite new to me too but I’ll do my best :P) ❤️


	2. Chapter 2

**Notes for the Chapter:**

> Happy Sunday! This is pure filth enjoy xx

He is all she can smell in this small space. His essence has permeated every bit of his car, and Theta inhales deeply, greedily, his coat around her shoulders, her small form wrapped in his Alpha scent as she shifts restlessly in the seat. It smells  _ so good.  _

She can’t help it. She brings the sleeve of his coat to her nose, inhaling deeply, then grabs the front of the coat and drags it to her face, almost gasping as she tries to drink in his delicious scent. She hasn’t realised she’s started rocking her hips, grinding against the seat of his car until Koschei swears and swerves suddenly, and Theta realises she’s distracted him so much he’s just run a red light.

“Can you stop that,” he mutters, “ _ please…” _

“Sorry,” she puffs out, but she can’t, she  _ can’t _ , she’s too needy, her body is aching and burning and his scent on the coat wrapped around her is like air to a drowning woman. 

“Theta,” he growls, his knuckles white on the wheel. Her eyes trail over his hands, his forearms, his muscles tense, veins standing proud and she imagines him gripping  _ her  _ like that - gripping her shoulders as he pressed her against this seat of his car - her neck - her  _ hips _ as he holds her body still and thrusts deep into her, filling her until she no longer aches and throbs -

“ _ Omega,”  _ he snaps, his voice suddenly sharp and angry, his tone commanding, “ _ stop that now!” _

She does. She whimpers, but she’s powerless not to obey his command, going still as she drops the coat from her hands and is left shaking on the seat of the car. 

“I’m sorry,” Koschei mutters, “I didn’t want to have to - but we were going to have an accident if you kept -“

“It’s fine,” she manages to rasp out. Her body trembles and her pelvis aches, slick drenching her thighs and Koschei’s seat (she’d be embarrassed if she were more coherent) and her blood rushes in her veins, nearly making her dizzy. 

It’s a blessed relief when they finally pull up outside her apartment building, and Koschei rushes round to open the car door for her and help her out. 

“Maybe - maybe don’t touch me,” Theta grinds out, her skin burning where it makes contact with his, sending her arousal spiking. She’s so wet now she’s sure it must be visible through her slacks - and even if it isn’t, Koschei can almost certainly smell it. 

Grateful for the coat of his thats big on her and comes down to mid-thigh, Theta hunches under it and stumbles to her front doors. Her hands shake too much as she fumbles with her keys, and Koschei takes them from her and hastily unlocks her door, swinging it open to let her stagger inside.

The room spins, and everything hurts and all she can think is  _ alpha knot mate,  _ as she inhales deeply through her nose. 

“Hot,” she moans uncomfortably, shucking his coat then peeling her shirt off over her head, stumbling on wobbly legs over to her sofa, hands unfastening her trousers.

“Jesus Theta,” Koschei curses form over by the door.

“So hot,” she moans again, kicking the slacks off and collapsing down, curling onto her side on the sofa, and it hurts, it  _ hurts _ … unfocused eyes find Koschei's, wide and dark, pupils blown large and breath coming out short. His scent fills the air of the small apartment and makes her dizzy, and she holds out a hand towards him. “Alpha,” she breathes hoarsely.

She sees him shake his head, taking a step backwards. That’s not what she wants. Alpha should be coming  _ towards _ her - why was he backing away? 

“Theta I need - I need to go,” he grinds out. 

“No!” The very thought feels her whole body with dread. A cramp rips through her, making her cry out sharply and scrunch her face up. “It hurts,” she whimpers.

“I’m - I’m sorry - I can’t -“

“Alpha please,” she moans, focusing dancing vision on him. She rolls off the sofa onto her hands and knees, and crawls across the carpet towards him. “I’ll be good,” she breathes, kneeling in front of him, slick drenching her underwear and sliding down her thighs. “I’ll be so good for you Alpha…”

She lifts her chin, tilting her head to the side and presenting her neck for him, her mating gland surely red and engorged with how hard it was throbbing. Her eyes flicker down to his cock, hard and huge in his trousers, and Koschei sways towards her before he abruptly rips himself away, turning and driving his fist into the wall with a yell.

_ Alpha doesn’t want you,  _ her hindbrain tells her.  _ You do not please him.  _

Usually, she hated the stereotypes. That Alphas were aggressive and prone to anger, and Omegas were weak and got anxious, especially before they were mated. But right now… right now she and Koschei are the epitome of that, as he paces, growling, practically vibrating with rage, and Theta kneels on the cold wood floor of her apartment, voice wavering as she begs him; begs for his cock and his knot to assuage the unbearable burning inside her.

“I have to go,” Koschei says, his voice choked and body trembling where he clasps the handle to her front door. 

To Theta’s utter horror, she bursts into tears. 

“ _ Shit,” _ she hears from across the apartment as she buries her face in her hands. Then suddenly, the Alpha’s heady, perfect scent is engulfing her, and arms are wrapping around her trembling form, lifting her carefully. 

He carries her through her apartment, murmuring to her, his voice low and soft as he tells her he’s “ _ sorry, so sorry, don’t be sad little Omega, Alpha’s here, Alpha will take care of you…” _

He sets her on her bed, and she looks up at him through blurred vision as her body screams in protest when he steps back from her.

She holds out a hand. “Please,” she breathes. Her thighs are coated with her slick, and she’s burning, aching, unbearable cramps ripping through her that she knows will only be soothed by one thing. 

“I’m gonna -“ he takes a step back. “I’ll run you a bath - cool bath - it should help -“

_ What?  _ No - that wasn’t what she needed! Alpha knew what she needed - why was he denying her? 

He’s gone before she can protest, leaving her groaning and shaking on the bed, curled into a ball as cramps tear through her body.

She’s drenched when he returns - with both sweat and slick, inner thighs sticky and underwear horribly uncomfortable as she tosses feverishly on the bed. He’s speaking, trying to tell her something, tone soft and coaxing but Theta can’t concentrate on his words, only on the unbearable knowledge that  _ her Alpha doesn’t want her.  _

_ “Get up,” _ He orders, the command cutting through the fog in her brain, and she’s doing it before she can think about it, despite the cramps that threaten to tear her apart. 

She can hear his voice by her ear as he guides her into the bathroom - she thinks he’s apologising quietly, but she doesn’t much care, letting him help her step into the bath, sinking down into the cool water in her underwear.

It does clear her head a little, dropping her temperature enough - at least temporarily - for Theta to regain some of her senses. She blinks over at Koschei, standing by the sink, gripping it tight with both hands, his knuckles white. He is visibly hard and straining against his trousers, and Theta swallows and tries not to look. 

“I’m sorry,” she manages to mumble, “It was stupid - forgetting my suppressents this morning.” She looks down, “I never meant to put you in this position.”

“It’s -” His voice shakes slightly, “It’s fine.”

“You should go,” she forces out, despite every one of her senses screaming at her to do the opposite. She knows Koschei would never have been here by choice.

He appears to hesitate. “Will you be alright?”

Probably not, and they both knew it. Well - literally, yes she would, it wasn’t like going through a heat alone had ever killed anyone, but it was certain to be extremely uncomfortable and painful, and from how intense this one was already when it had barely even got going, Theta knows she is in for a rough few days.

_ No,  _ she wants to say,  _ stay, please - help me through it Alpha…  _ she squeezes her eyes shut as another wave of cramps grip her, and she moans, shifting in the bath, the cool water heating rapidly around her burning form. 

“Theta?”

He takes a tentative step closer and she inhales deeply, the scent of him filling her up and making calm wash over her just a split second before she realises that he  _ isn’t  _ here to soothe her. He’s leaving.

“Please,” she utters.

“Please what?”

_ Please go now, _ she has meant to say. She’s sure that’s what she’d meant to say but - but Koschei has stepped even closer and suddenly all Theta can see and smell and breathe is  _ him  _ and -

“Help me,” she whimpers instead. 

Koschei falls to his knees beside the bath. 

“I - shouldn’t.” It isn’t  _ can’t  _ anymore, she notes.

Theta groans, shifting in the tub, feeling slickness rush from her in this proximity to him, tangible even in the water. “I need you,” she whispers.

“It doesn’t - it would be a good idea. Us,” he says with his knuckles white where they grip the edge of the tub. His breathing is laboured, pupils dilated, and Theta knows that if she leaned over and glanced down into his lap she’d surely see him leaking through to his trousers already. It certainly smells like it. 

“Not to mention work,” he’s continuing, “they - we - everyone will know if I spend this heat with you, my scent will be all over you for days and yours on me - you know that -“

“I don’t care, let them,” Theta babbles, “let them know I’m yours, I want them to know, want everyone to know…”

“ _ Fuck,” _ he drags a hand over his face, “Theta, you’re not - your job. They’ll find out you’re an Omega - you can be fired for that, for lying about your designation - you know that!”

“Don’t care,” she mumbles, she’s up on her knees in the tub now and leans into him, rubbing her neck against his, purring at the back of her throat. “Don’t want it, want you, I’ll stay here, be here for you whenever you want Alpha…” it isn’t Theta talking anymore, and somewhere in the back of her mind she’s aware of that - that this is the Omega part of her brain that’s taken control of her now… but Theta can’t seem to find it within herself to care anymore. 

Koschei lets out a groan, and cups her face in his hands. He shakes visibly, his eyes dark, pupils blown wide. “That’s not what you really want,” he utters. 

She nods. “It is. You are. I want your cock and your knot… I  _ need it _ … I need your cum inside me, filling me, please, fill me up, make me full, it hurts so much…”

With a growl, Koschei bodily lifts Theta out of the tub, ripping her panties down her legs and clawing at her bra until both scraps of sopping fabric are gone. He picks her up and staggers with her, over to the sink counter where he deposits her, sinking immediately to his knees and pressing his face between her legs like he can’t bear not to be there for a second longer. 

His face… oh, his  _ face…  _ his beard is rough where it scrapes against her, delicious friction where his tongue is hot and soft, and he licks and sucks and kisses like he can’t get enough of her taste. 

Pleasure rolls through Theta in relentless waves, making her shout and keen, hands gripping the edge of the counter desperately for purchase as Koschei attacks her with his tongue. The wet sounds his mouth against her slick are making are obscene, and Theta hears him swallow loudly more than once - swallowing  _ her _ , drinking from her like he cannot get enough. Even though Theta had never let someone near her during her heat again after that first time (too afraid of being so desperately out of control and vulnerable), Omegas were generally prone to producing a lot more fluid than Betas, and the Betas she had been with had always seemed to find that a little alarming - even off-putting a couple of times. But not Koschei. This Alpha drinks from her like he is dying of thirst and she is the sweetest nectar, humming in satisfaction as he laps at her, lips, tongue and even teeth scraping lightly until the coil in Theta’s belly snaps. Her thighs lock around his head when she comes, body shuddering as he laps rapidly at her clit, and even more slick drips from her, pooling on the countertop beneath, soaking his neck and chin. 

He stands between her legs when he’s done, and Theta’s shaking hands are already at his belt as she eyes the glistening evidence of herself on his face. 

“Are you -?“ she asks desperately, almost beyond words as she palms him through his trousers.

“If you’re asking if you’ve sent me into rut,” he says lowly as he hastily shucks his shirt and unbuttons his trousers, “then the answer is  _ yes.”  _ He pushes them and his boxers down, kicking them away. “Yes you have.” He grabs her hand with one of this own, pulling it to him, letting her feel the thick hardness of him, rubbing it over the base of his cock where the promise of a knot is already starting to swell. He’s red and engorged and weeping precum all over her hand, and Theta squeezes him, marvelling at how her little hand doesn't even reach all the way around him. She throbs between her legs in response, her tight channel clenching in anticipation of all of that filling her up. With the other hand, he grabs a fistful of her hair, yanking her head back sharply, making her cry out as he leans in and scraps his teeth over her throat, inhaling deeply. 

He thrusts eagerly into her hand. “This is what you’ve done to me,” he growls into her skin, turning his head to lick at her just beside her aching gland. “And now you’re going to be  _ fucked,  _ little Omega.”

Theta whimpers as he pulls her off the counter by her arm, spinning her and pushing down between her shoulder blades so she collapses over the cold hard surface. Her stomach squelches against the little puddle of slick she’s left behind, and more of it trickles down her inner thigh making her groan with want. She’s about to start begging for her Alpha again, when Koschei grips hold of her by the waist and finally -  _ finally  _ pushes inside.

She’s in heat but it’s still been a while since she’s done this - even longer since she’s taken anything the size of an Alpha cock on its way to full rut, and she gasps, hands scrabbling on the smooth surface for purchase as he opens her up. He slides all the way in, swearing, muttering, filthy things about how tight she is and what he’s going to do to her. He isn’t gentle when he starts moving, thrusting into her fast, and Theta lays her cheek on the countertop, spreads her legs and takes it, her Omega brain screaming out in delight as her body finally gets what it’s craving. 

“Good girl,” he pants behind her, “such a good Omega - so good for me…”

Theta’s whole body reacts to his words, a shudder going through her as she feels herself clench around him and then get taken by a climax that comes out of nowhere. Koschei is stroking her back and her hair when the waves pass, his gentle touch a contrast to the punishing rhythm he sets inside her, shoving her hips into the counter with each bone-shaking thrust, almost as if he’s apologising for the way his body forces him to take her. It’s not necessary; Theta’s whole form sings with bliss as he fucks her, her breasts pressed into the cool marble of the countertop, eyes glassy and mouth open, uncaring of the drool that slips from it and pools beneath where she lays her cheek. 

He’s fondling her neck now, fingertips brushing and stroking the glands on either side and she moans louder, stretching her neck, bearing her mating gland to him. It throbs, tingling, like an itch begging to be scratched.

Koschei is steadily building closer to his own climax, she can feel it in the way his thrusts speed up and lose their rhythm every several, and she braces herself, ready to feel the press of his knot inside her, aching to feel it fill her and swell inside, to feel him finish in her, soothing the burning inside of her with his seed.

It doesn’t come. Instead, Koschei pulls out, letting out a growl that sounds pained, and Theta whimpers in protest, because it’s  _ not what she wants - _

“No,” she moans, squirming beneath him, “no please - knot -“

She feels a large hand stroke up over her sweating back. “Not here sweetheart,” he grunts.

“Then take me to -“ she begins, but it’s too late, he’s rutting against her, cock sliding through her folds and the crevice of her arse, the bottom of his knot bumping against her entrance as he thrusts helplessly against her, and then he’s coming. And she’s coming, empty cunt clenching around nothing as she shudders and screams and Koschei spills out all over her lower back and behind. He holds her in place a moment, one hand on her hip as he withdraws enough for her to feel the last few spurts of cum land on her cunt, and then his fingers are there, rubbing at her, dragging another sputtering climax from her as he presses them inside, pushing the hot stickiness of himself into her. He’s tracing circles on the bottom of her back with slick fingers when she regains her senses, and she shudders, body delighting in the feel of him smearing himself over her. Marking her. 

She makes to push herself upright when another cramp grips her, and she cries out, collapsing back down, whimpering helplessly.

“I need -“

“I know what you need, love,” he’s stroking sweat damp hair back from her neck, hands gentle and soft.

“Your knot - Alpha please -“

“Shh,” he soothes, “hush Omega. Let me take care of you. I’ve got you.” 

She is boneless as he tugs her up by the arm, and then scoops her up, carrying her through to her bedroom where he lays her carefully on the sheets. She looks down as he crawls up over her and kneels between her legs to appraise her, his cock still engorged and throbbing, weeping with precum despite having just climaxed as he rubs a hand over himself. She knows, more from what she’s heard than experience, that he’ll stay hard for hours in this state, able to fill his Omega up over and over with his seed, gaining brief refractory periods only after he’s fully knotted and emptied inside her.

Theta lays back for him and spreads her legs, pushing her hips towards him. She knows her cunt is pink and sodden and swollen, and she slips a hand down between her legs, parting her lips for him with two fingers. More slick gushes out, running down between her bum to drip onto the bed sheets, and Koschei makes a strangled sound, pumping his cock faster in his hand before he lets himself fall down over her, hands braced beside her head. 

“Look at you,” he growls into her throat. His teeth scrape over her skin. “So needy. So good for me.”

Theta nods frantically, clutching at his back, trying to pull him closer. She needs his knot - she  _ needs it.  _

The tremors in her limbs subside a little when he presses into her again, and she locks her legs around his waist, moaning happily as he fills her. 

“Please,” she pants this time, when his knot starts bumping against her entrance. She tilts her hips, begging for him to press in. 

But to her utter frustration, he doesn’t.

“ _ Koschei,”  _ she growls, digging her little nails into his back. She drags them down, scraping, uncaring if she hurts him. By the way he growls into her neck she suspects he likes the sting.

“ _ Omega,” _ he scolds, lifting his head to stare down at her with dark eyes.

“I need -“

Koschei lifts a hand from the bed and presses it to her neck, fingers squeezing either side of it. 

“You  _ need  _ to lay still and let your Alpha  _ fuck you _ , little one.”

“But -“ she tries to get out, but Koschei squeezes harder as he fucks her faster, and Theta’s head spins. She’s so slick around his cock that he slides in and out of her as if her cunt were hot butter, more lubrication rushing from her, soaking the bed beneath them, her body desperately preparing for the knot that her Alpha refuses to give her. She  _ needs it  _ \- she needs to feel his body locked to hers, needs his cum deep inside her, for his hot seed to soothe the unbearable ache in her womb. 

Her hands have gone to his wrist as he squeezes her neck, and she feels the tenseness of his muscles there, the strength of the arm that holds her down. Her Omega delights in it, singing happily inside her head;  _ Alpha is strong, Alpha will protect you, give you strong young and protect them too…  _

She gasps, trying to shake the thoughts from her head, but her body is having none of it, demanding angrily that he fill her  _ right now  _ when she’s ripe and ready for his seed.

“Pluh -“ she pants, struggling to take deep breaths with his hand on her neck.  _ Please,  _ she whispers instead inside her head, willing Koschei to hear her.

He doesn’t. Or he knows her wish and ignores her still, his whole body going tense over her as Theta’s form shudders violently with climax, then he comes with a roar, starting to spurt inside her before he withdraws his rutting hips and spills the rest all over the quivering muscles of her stomach. 

Theta is gasping when he releases her neck, and rolls off her to collapse on his back.

“You didn’t knot me,” she accuses, tears stinging in the corners of her eyes. 

Koschei lays silent beside her for a minute, panting harshly, and she thinks he’s going to say something when he rolls over on top of her again, sliding down between her legs this time and pressing his mouth to her aching core again. She comes around three of his fingers this time, but still it is not enough.

—

Theta is exhausted by the following evening. Koschei has stayed and pleasured her, every which way, over and over again, wringing so many climaxes from her body her nerve endings are raw with it, but still he refuses to knot her. 

She feels as frustrated as when she’s forced to endure her heats alone, with nothing but a dildo and her hands and an empty bed beside her.

Koschei clambers out of bed to get some food for them from the kitchen at some point, and comes back to find that Theta had raided her bedside drawer in desperation, and is plugged with her knotting dildo, gasping lightly amongst sweaty sheets. It’s still not enough - her body knows it isn’t Koschei, knows it hasn’t had what it desperately needs as she holds out a hand towards him, her inner Omega screaming for  _ Alpha Alpha Alpha.  _

He stares between her legs, plate of food forgotten in his hand. 

“Is that - ?”

She nods. “You would feel better, Alpha,” she purrs lowly.

After a moment he gives himself a shake and crosses the room, setting the food down beside her bed and crawling up to nuzzle her neck. “Come, eat something,” he purrs to her, hand drifting down between her legs to tap where the toy is nestled inside her. “Then I’ll fuck you with this properly.”

That isn’t what she meant and they both know it, but Theta lets him ease it out of her, lets him prop her up with pillows so he can feed her from the plate of food he’s brought. She delights in him catering for her needs even as she wants to cry in frustration that he continues to deny her his knot.

_ Alpha doesn’t really want you,  _ that horrible voice inside her head tells her over and over. 

—

“You said you’d take care of me,” Theta sobs later that night after he’s come on her thighs and cunt before collapsing over her, tears on her face and accusation in her voice.

“I know, I  _ am,”  _ Koschei presses the words into her breast, mouth by her nipple.

“I need your knot,” she begs for the hundredth time, “why won’t you give it to me?”

“I  _ can’t.” _

“Why!?”

He mumbles something into her skin that Theta thinks sounds like “ _ because you’re not mine.” _

“I am yours,” she answers it anyway, nails digging into his back, “I’m all yours, all of me, please, I need you…”

Koschei falters, and Theta thinks she hears him growling quietly into her skin, his breath puffing against the underside of her breast before he bites down, hard enough to make her yelp, and then he’s tearing himself away from her and dragging her by the arm off the bed clumsily to her feet. He yanks her across her room, shoving her into a wall and fisting both hands in her sweaty hair.

“If you’re mine then get on your knees and prove it Omega,” he growls, his dark eyes flashing with danger.

Theta does, sinking immediately to her knees in front of him with a whimper, something inside her chanting like a mantra:  _ please Alpha, obey Alpha, please him and he will give you what you need… _

One hand still fisted in her hair, so tight her eyes water as he forces her to look up at him, Koschei grips her jaw with the other and presses his thumb between her lips.

“Open your mouth.” She does, letting him pull it open, thumb hooking round her bottom teeth and dragging as he guides her to his erection. He presses in, dragging her down so quick onto his massive cock that she gags, eyes watering, spluttering around him. 

He appears to falter, some of the franticness flickering from his gaze, and Theta hastily lifts her hands and grips ahold of his backside, moaning as she moves her head back and takes him inside again. Koschei lets out a low groan, the hand releasing her jaw to brace himself on the wall behind her, the other still gripping her hair but loser now, letting her set the pace and move as she wants over his length.

She’s only done this a few times, and Koschei is huge inside her mouth, but Theta makes herself relax her throat and take him in as deeply as she can, that desperate need to please him hammering inside her skull. Her cunt burns with emptiness, and she whimpers as slick runs down the inside of her thighs, feeling her inner walls clench tight and contract around nothing as her body reacts to the feel and taste of Koschei in her mouth.

He howls when he comes, his thick cock inside her mouth and her hand wrapped around his knot, squeezing and kneading the hard swollen flesh as she swallows every drop of cum he spills into her mouth. Her lips are swollen when she releases him, and she looks up with glazed eyes at him as she licks at his tip, gathering a few remaining drops of his seed on her tongue and swallowing those down too. Her body wants to be full of him, but not like this. She squeezes his knot and gets another spurt of cum as a reward, and gathers him on her hand, pushing it quickly down between her legs and rubbing the hot liquid against her slick. Koschei growls as she pushes two fingers inside herself, brushing his thumb over her swollen lips, collecting a drop of cum from her cheek beside her mouth and feeding it to her.

Theta looks up at him, eyelids fluttering, dizzy with want. 

“Please,” she utters.

Koschei’s shoulders sag. “Get on the bed,” he tells her.

Gazing up at him, Theta drops onto her hands and slinks past him to crawl across her bedroom carpet towards the bed. She hears Koschei swear behind her and knows his eyes are on her cunt and the slick that glistens there and on her thighs. She crawls up onto the bed, laying down on her back, arching and baring her belly and her neck and her cunt to him submissively. 

Koschei stands and looks at her for a moment from across the room. His mouth is hanging open, and despite the recent orgasm, his cock is hard and weeping, ready for her again. She knows denying them both his knot for this long must be painful for him too. 

Theta swallows, and tries to clear her head through a mess of hormones.

“It’s okay you know,” she says quietly.

“What is?”

“This,” she motions between them. “Us, now.” Her eyes flicker down to his cock. “It’s just… hormones, right? Chemicals. You can let go, and I won’t judge you.” She snorts, “you’ve already seen me at my absolute worst.” It hurts her to say; to admit out loud that she knows he doesn’t want her, not really. But Koschei’s Alpha is fighting for control now, she can see it in his eyes, and his Alpha  _ does  _ want her… at least right now. Theta spreads her legs wide and trails her hands up over her naked form.

“I don’t think this is you at your worst,” he says, surprising her as he moves towards her.

She blinks at him as he crawls slowly onto the bed with her. “No?”

He shakes his head as he settles over her on his hands and knees. “No. Your worst was definitely when we raided the school supply closet when we were ten and you ate so much chocolate you were sick.”

Theta gasps, smacking his shoulder as her face flushes.

“I can’t believe you remember that,” she laughs.

“Difficult to forget. Especially as most of it went on me.”

She groans, throwing an arm over her face to cover her eyes. “I hate you.”

“That wasn’t what you were saying a minute ago.”

“I still want you to fuck me,” she mumbles under her arm, “but I also hate you.”

“Well.” Koschei replies, and leans down to nudge his nose into her neck. “I can help with the first one, at least,” he says quietly. Theta doesn’t have a moment to think on his words before he lowers himself over her and she feels the slide of his cock through her dripping folds. He pulls her arm from her face, making her look him in the eyes as he pushes into her, beginning to fuck into her steadily. His dark eyes grow darker, eyelids drooping and jaw slackening as he chases his pleasure inside her, and Theta lifts a hand, equally as drunk on the sensations as she brushes hair back from his sweating face.

“You want me to knot you?” She almost misses the quiet murmur as Koschei snaps his hips a bit harder into her own, and she feels the pressure of his knot against her entrance. 

“Yes!” She gasps, heart leaping in her chest. “Yes  _ please _ …”

“Are you sure?”

How can he ask that? She’s in heat! Her whole body is screaming for only one thing - why is her Alpha denying her? “Yes! Knot me,  _ please Alpha!” _

“Theta,” he breathes into her neck, breathing ragged. His teeth scrape again - so close to her mating gland this time. She whimpers. “Has there - has there been anyone else?”

She inhales sharply at his question, the intensity behind it striking her even through the fog of hormones in her brain. 

“ _ Tell me!”  _ He growls when he doesn’t answer, and she finds herself shaking her head, clinging to him.

“No!” She gasps. There hadn’t - only a handful of Betas and that didn’t count. That wasn’t what he meant. “Only you, Alpha, I’ve only ever taken your knot - only wanted yours…”

He groans aloud at her admittance, and then his hips are pressing into her harder and his teeth are sinking into her shoulder, and she - there’s a moment where she thinks he won’t fit, when the stretch of her body feels impossible as he tries to work his knot in, and she tenses, nails digging into his skin as she gasps and whimpers. But then his teeth release her shoulder and his mouth is on her gland, tongue lapping gently over the subtle bump of a very old scar, soothing, sending waves of pleasure thrumming through her as his thumbs stroke circles on her hips.

“Relax,” he murmurs into her neck. The vibrations of his voice against her gland makes her gasp again, toes curling, “I’ve got you, you’re doing so well, you can take it…  _ there _ ,” he sigh as he finally eases into her, and then he’s nestled inside, swelling steadily in her body as her muscles clench around him, locking them together. Theta is sweating and her body shudders with pleasure-pain as Koschei murmurs softly to her.

“Taking me so well,” he praises as he lifts up on his forearms to look down at her. “You’re perfect, Omega.” 

Her hindbrain preens at the praise, and she arches beneath him, willing him to move. 

He does, and Theta thinks she’s never felt such perfect pleasure. While his movements are limited to small rocks of his hips now he is locked inside her like this, he is hitting her  _ so deep _ now, the head of his cock bumping right up against her cervix, making her every sense center on  _ him,  _ Alpha, Alpha inside her, where he belongs. 

He reaches round beneath her and grips her backside, then he pulls her up, raising himself up and back so he’s sitting on his heels and her pelvis is hitched up in his lap, hips open and legs splayed wide as he ruts into her. Theta’s whole body shakes, and she struggles to raise herself up on her elbows to look at where their bodies are joined, moaning at the sight of her lower abdomen bulging slightly as he moves within her, the outline of his huge cock visible through her. 

“Alpha,” she coos, delirious with heat and pleasure, “cum in me, I need you, need to feel you come, I need you to fill me up Alpha  _ please - _ “

Koschei gives a growl at her words, gripping her tightly and leaning forward over her, putting force behind his movements and ensuring that he’s striking her clit as he slams against her. Once, twice -

“Come around my knot Omega,” he demands, “ _ now!”  _

She does. She comes, and comes, her Alpha giving a roar of his own as she feels him swell impossibly larger and then spurt into her and  _ Alpha Alpha Alpha  _ as all she can think, but it is the name Koschei and not Alpha that she screams as she shakes beneath him. 

—

**Notes for the Chapter:**

> Thank you for the enthusiasm on the first chapter! I really hope you're all still here 😂 Pleeease leave me a comment and let me know if you liked it, it's kind of nerve-wracking posting something so different haha 😅🖤


	3. Chapter 3

**Notes for the Chapter:**

> Some more porn with a side of feelings x

They don’t speak much after the first time he knots her, both equal parts exhausted from their vigorous, intense sex and feeling a little awkward when the first buzz of chemicals simmer down inside their brains and bodies. 

Theta wants to say sorry again. Sorry for forgetting her suppressant and going into heat at work. Sorry for dragging him into it. Sorry for triggering his rut and forcing him to stay and see it out with her together. Sorry for making him bite her ten years ago when they’d just been children and lost to their instincts, sorry she was never the Omega he wanted...

But she doesn’t. She doesn’t say any of it. They just lay there, locked together, hands tracing skin absently until her insides start to burn again, fire prickles beneath her skin and slick pours from her anew. Koschei slips out of her, only to grow hard again almost immediately and then she’s in his arms again, moaning, and it doesn’t matter what she thinks anymore.

Theta loses time. 

She lets him do what he likes. She lets him fuck her, and knot her, over and over. Her mouth, her cunt, her arse. She lets him turn her on her belly and fuck into her with her face pressed to the pillows, lets him push her on her back with her legs over his shoulders. She climbs on top of him when her drags her over him and sinks down eagerly on his huge cock, she lays for what feels like hours of bliss with his head buried between her thighs. She lets him come all over her, marking every inch of her with the very essence of  _ him _ , and scratch days, she will smell like him for  _ weeks  _ after this - and Theta has never been more glad of anything. 

She’s not sure when it is, sometime late on the second day, or perhaps deep into the night, when they are finally both lucid enough to at least be aware of their surroundings, content to lay still with him still knotted inside her as they catch their breath. Theta’s body thrums pleasantly, all her Omega senses well sated for now, happy to have her Alpha inside her, having taken care of her and the promise of more to come when she needs it. Which likely won’t be long. 

Her mind rushes back through the previous two days. She knew she should be embarrassed, by the way she’d thrown herself at Koschei, but then… it wasn’t like it was something she could control. Like her, he was just as much a slave to his body’s needs. He would understand. They both knew full well that the rational parts of their brains didn’t have control when heat and rut took hold. She thinks back to the things he’d said, the words he’d uttered, growled, bitten into her skin as he had moved over her. Most of it nonsense, quiet praises and filthy utterances of what he was going to do to her that made Theta’s body sing. But something stood out, something that he had made her admit before the first time he knotted her that Theta now, with a clear head, feels a little embarrassed about. Still, she can’t help but remember the intensity in his voice as he’d commanded her to tell him, the way he’d bitten deep into her flesh in approval when she’d given him the answer he so clearly wanted. She knew, rationally, that it was probably just standard Alpha possessiveness, one of those primal urges he couldn’t control while he was in full rut on top of an Omega… but Theta wonders. 

Just like he is reading her very mind, Koschei picks that moment to clear his throat in the dark of the room, and voice the exact topic she’s pondering. 

“You’ve really not been with another Alpha?” His voice is scratchy and quiet in the room, only the sound of their laboured breathing accompanying it as she lays on top of him. He speaks the words like he knows he shouldn’t say them, but cannot stop the burning curiosity from leaking out. Theta keeps her head tucked into his neck so he can’t see her face and shakes her head. 

“Wouldn’t lie to you,” she mumbles.

There’s a pause as Koschei trails his fingers up and down her spine, making warm shivers go through her, and she nestles deeper into his embrace.

“Have you?” She can’t stop the question slipping out, despite not being sure whether she wants to know. “Been with other…” She lets her words trail off without finishing her sentence.

“I…” there’s a pause, and she feels her chest do something funny. Something painful.

“Forget it,” she mutters, “of course you have.”

“No I…” he sighs, laying his hand flat on her back. “I’ve been with other Omegas,” he admits quietly, and Theta finds herself nodding quickly, ignoring the way her stomach drops because of course -  _ of course  _ -

“But I’ve never knotted anyone else.”

Her thoughts stall at that, and after a pause she lifts her head to look down into his face in surprise.

“You haven’t?”

Koschei shakes his head, a frown drawing a line between his eyebrows. “It didn’t feel… there wasn’t -“ he cuts off again, and gives a huff as if he doesn’t know how to explain himself. His eyes dart about, avoiding hers. “I just couldn’t do it,” he finally mutters, “not after that first time.”

Theta’s lips part as she stares down at him. She swallows hard. They’ve never spoken of it. Never even referenced it, not directly. The closest they had ever come to acknowledging that it even happened was Koschei’s ‘ _ I should know’  _ on her first day at work. 

She lifts a hand to trace the sharp edge of his jaw, eyes following her fingers instead of looking into his own. “Not the happiest of memories, huh?” She admits quietly, and sees his throat bob as he too, swallows.

“Not what happened afterwards, no.” 

Her fingers pause, and she bravely lifts her eyes to his. “But… we are now. Knotted, I mean.”

He gives a slight buck of his hips that makes her gasp and clutch at his shoulders. There’s a tiny smirk on his lips now. “I’d say so love, yes,” he teases. 

She gives a small huff, rolling her eyes. “And… how are those memories?” She asks quietly.

Koschei shrugs slowly, the smile falling from his lips. “How are yours?”

Theta copies him, and shrugs. “Just don’t try and pull out of me until it’s gone down.” She tries for humourous, but her voice comes out a little too dry, a little too much of a hurt edge to her words. She drops her head again, laying it on his shoulder and turning it away from his searching eyes. The hand on her back smooths up over it slowly.

“Did I hurt you very badly?” Koschei whispers. 

Theta gives another shrug. “Was a long time ago now. Don’t really remember. I was in heat and… my head was a mess, afterwards.”

Koschei gives another one of those audible swallows. “I don’t blame you, you know.”

Theta blinks. And blinks again. 

He…

He doesn’t  _ blame her?  _ Like he should? Like he would have a right to? Her whole body goes tense, chest clenching tight.

“Good because it wasn’t my fault,” she says sharply. What makes him think - !?

“No I know. It wasn’t. I just wanted you to know that.”

Theta suddenly wants him out of her. She wants to be away from him. She sits up, tugging, and they both gasp.

“Ah ah,” Koschei’s hands immediately go to her hips, holding her down. “It's too soon. What are you doing?”

“Make it go down,” she snaps, trying to get out of his grasp. 

“I  _ can’t  _ Theta - what are you -“

“I want to get off, I want you out of me, I want -“

“Shhh,” subduing her the only way he can as her frantic voice rises, Koschei twists her beneath him, leaning in and closing his mouth over her mating gland. She whimpers, and he sucks at her there, laving his tongue over the pulsing skin and suckling gently at her until she feels her body go limp and relaxed beneath his. Damn him. Damn her biology that forced her to submit to him like this. Damn all of it. 

She’s crying again, and damn that too. She hates hormones - she hates all of this. 

And now her hips are rocking beneath his, and he’s growing harder inside her again, and she hates that she wants him even as she wants to get out of this bed and away from him and run until she never has to see him again. 

“Please,” she utters instead, body shuddering with need, already clenching around him. Koschei dips his head from her gland, and sinks his teeth into her neck below it instead as he starts rocking inside her. 

They don’t speak afterwards this time, she just lays on top of him where he rolls them so his heavy form doesn’t crush her, face turned away, and Koschei strokes her back and fiddles with her hair until he has finally softened enough to ease out of her. She slips out of the bed, and rushes for the bathroom, locking the door behind herself and sliding down it to the floor.

Theta had always thought Koschei was different. Alphas were all the same - they believed they ruled the world - on that, she supposes, he was just like the others - but Alphas (and a lot of the Betas she’d met too) always thought that Omegas were somehow…  _ less _ than them. That they were weak and needy, required protection and reassurance, only able to live free and happily once they were mated. Theta never thought Koschei would think of her that way. And despite what had happened between them, despite the fact that although they’d been friends, she clearly wasn’t the one he wanted as a mate, Theta had never thought (probably foolishly, she realises now) that Koschei would assume she believed it was her own fault. That she was somehow inadequate, just because he didn’t want her. Like his wanting her was the thing that would give her worth. 

She brushes at the tear that slips down her cheek. Stupid. And now she was trapped here with him, her in heat and him in rut, and any minute now she’d be a slave to her body’s whims again, begging him to take her, begging for the validation he so clearly believed she needed.  _ She hates it _ . 

“Theta?” He knocks on the door. “Are you alright?”   
“Yes,” she calls back through so he doesn’t try to come in. She pulls herself off the floor and turns on the shower, emptying her bladder quickly and washing her hands before she steps under the cool spray. It’s probably pointless, washing him off her skin when he’d be all over her again in just a short time, but right now, Theta scrubs at her body, wanting every trace of him gone from her. 

The lukewarm water is like ice on her burning skin, and Theta groans, already feeling an ache in her belly, her nerve endings starting to scream out in protest at being separated from her Alpha.

She splays her hand across her abdomen where it hurts, nails digging into her skin like she can claw the feeling from her. The longer she stands under the spray of the water the more impossible it feels, and she starts to sweat. She’s reminded painfully of that first time - her first heat when she’d been torn from a new mating bond, how much it had hurt her, physically and mentally to be separated from him, days spent shaking and crying out for him to an empty room.

She whimpers, dropping to her knees, wrapping her arms around her middle and hunching over as emptiness washes through her and irrational panic starts to rise in her chest.

“Theta?” He bangs on the door, and she fights everything inside her to remain on the floor of the shower instead of going to him like her instincts demand. “What’s wrong? Theta!” He bangs on the door again, harder this time. “You smell - wrong… open the door!”

She knows her distress is making her scent spike, knows it’s probably doing things to Koschei trapped on the other side of the door but she  _ can’t  _ \- she can’t do this with him again.

“Go away!” She calls out, her voice a lot weaker than the determined snap she’d intended.

“What’s going on? Why won’t you let me in - you need me - I can smell it… Theta!”

She can scent him too now, smell the panic rolling off him in waves, and everything in her screams at her to go to him but she can’t - she  _ can’t.  _

He bangs on the door, harder this time, nearly shaking it in its frame, shouting at her, demanding she let him in again, and she’s upset and confused and she  _ doesn’t want _ … but the anger he’s throwing out sends heat shooting straight through her body as she gasps, slick flooding from her, coating her thighs and dripping down where she kneels on the floor of the shower.

“ _ Damnit Omega open this door!” _

She stumbles to her feet, lurching from the shower, almost slipping on the tiles as she grabs for the door, hands shaking as she twists the lock and then  _ finally  _ \- he’s bursting in, grabbing for her, picking her up and rushing forward, back into the shower where he slams her against the wall. 

Her legs go round his waist, arms clutching at his broad shoulders, hips tilting into him so she can take him inside, throwing her head back against the tiles as growls into her neck.

“ _ Why wouldn’t you let me in _ ?” He’s calming now, the frantic panic easing from his scent as her hot body envelopes him, but he still smells upset and confused, and Theta chokes back a sob, compelled by an urgent urge to soothe him.

“I’m sorry,” she gasps, “I’m sorry Alpha.”

—

Koschei’s shut the spray of the shower off and somehow had the sense to grab the towel off the hook outside the glass door before sliding to the floor with Theta in his arms. They sit panting, his back against the wall and her astride his lap, his knot locked inside her as he rubs her back through the towel he’d thrown over her.

“Sorry,” he mumbles, “not the best place… I think we should be able to separate in a minute.”

Theta nods wordlessly, leaning against his chest. Their bodies still twitch where they are joined, small aftershocks of pleasure going through her which make her tighten around him, squeezing him, and she feels more of his cum spurt into her. It soothes her whole body, makes her feel warm from the inside, and despite the turmoil going on inside her head, she moans contentedly, burrowing into his shoulder. 

After a moment, he clears his throat. “Do you… want to talk?”

She shakes her head.

“Okay.”

“I think,” she manages after another minute, her voice hoarse and dry. “I want to sleep. For a bit. Can we?”

“Of course, love.”

When Koschei eases her off him, he grabs the towel before it can slip and wraps it round her, before lifting her off her feet and carrying her back to bed. She should protest, really, but she’s too tired not to be grateful as he tucks her under the sheets. 

“No,” she gasps before she can stop herself, clutching his wrist when he goes to move away.

“Just going to fetch you some water, and something to eat.”

“Don’t want it.”

“Two minutes,” he says firmly, wriggling his hand from her grasp and slipping away. 

She must fall asleep while he’s gone, because the next thing she’s blinking her eyes open, and light is seeping in round the edges of the drawn curtains as a hand brushes hair from her face.

“Time’s it?” She mumbles. 

“Early.”

Koschei’s voice is rough and strained, and when Theta drags herself fully awake she sees him sitting on the bed next to her, hard and engorged, weeping already, so red it looks painful. 

“Should’ve woken me earlier,” she mumbles, rubbing at her eyes.

“You looked tired. And you need to eat and drink something before we fuck again.”

He presses a glass of water into her hands and she drains it quickly, then he’s lifting a piece of fruit to her lips.

“Don’t want it,” she shakes her head. Her body is waking up too now, aching and burning, senses tingling as arousal grips ahold of her fast, her empty cunt starting to throb. She reaches for him. “Need you.”

She refuses to eat until he demands it in a tone that forces her to obey, and Theta hastily scarfs down some fruit and a breakfast bar, and another half glass of water before Koschei sets the plate aside and pushes her down onto her belly. 

He still fucks her quick and hard, but he seems calmer this time, the edge of frantic desperation worn off, and he doesn’t knot her, finally pulling out to spill over the backs of her thighs and her arse, his hot seed dripping down between her legs. He rolls to his back with a sigh afterwards, laying beside her as they catch their breath, and Theta turns her face the other way.

“Not much longer now,” he comments. “You?” He says when she doesn’t reply, and she shrugs. Koschei knows anyway. He can scent how close to the end of her heat she is, just as surely as she can with his rut. 

“Tonight, maybe. If we’re lucky,” he continues. She hears him roll and shuffle to swing his legs from the bed. “Then I can be out of your hair.”

A tear slips down her cheek as Koschei swipes the glass of water and plate of food off the bedside table to the floor with a crash, and stomps off to the bathroom and slams the door. 

—

“I’m sorry for before.”

Theta starts awake again at the low voice, surprised to find Koschei kneeling by her bed. Not dressed, as such, but with his boxers and unbuttoned shirt on, at least.

“Huh?” Is all she can manage.

“I snapped at you, earlier. And I shouldn’t have. You’re under no obligation to want me here any longer than’s necessary. You didn’t mean to go into heat around me, after all.”

Still sleepy, Theta blinks, trying to make sense of his words.

“Okay,” is all she manages.

He seems to have cleared up the mess he’d made earlier, and a fresh glass of water sits by her bed.

“How do you feel?”

She takes a moment to think, turning her senses inward. “A little better, I think.” She shifts in the bed, and the sheets irritate her heated, sensitised skin. She shoves them off. Koschei’s eyes flick down and over her body, and some stupid voice inside her pipes up  _ do you like what you see, Alpha? Tell me I’m good enough, tell me I please you… _

“Do you need anything?” Koschei’s low voice interrupts her thoughts.

She swallows hard, moaning a little as she feels slick gather anew between her legs. 

“Can you…” she trails off, biting her lip. Does she have any right to ask for that? Hasn’t she already taken enough from him that had he been in his normal state of mind, he wouldn’t have been as willing to give?

“Yes?”

But Theta is weakened, though, and the Omega inside her wins this one. “Can you use your mouth on me? And then… and then maybe fuck me again...”

“ _ Theta _ ,” he practically growls, grasping her under the knees and pulling her to the edge of the bed, spreading them wide, “I would love nothing more,” he swears, before burying his face between her thighs.

“You taste so good,” he mumbles against her, spreading her open with his thumbs so he can lap deeply at her, inhaling as he does so. 

Theta tips her head back and gasps, eyes sliding closed as she gives herself over to the sensations of his hot, wet mouth on her. He’s insanely good at this - or perhaps any mouth would feel like heaven to her in this state, but for the moment, Theta is content to believe that her Alpha is the most talented in the world. 

_ Her Alpha. _

She knows that’s her Omega hindbrain talking, but Theta also admits that she cannot see herself ever thinking of another Alpha as ‘hers’. It didn’t matter that Koschei didn’t want her - and that after this, they’d likely go back to mostly ignoring each other at work (her stomach clenches with anxiety at the thought), a part of Koschei would always be hers… just as surely as a part of Theta had belonged to him since that day behind the school field when they were fifteen years old.

Her mating gland itches, and she lifts a hand to rub at it, hissing as her fingers make contact with tender, sensitive flesh. It’s hot and swollen, and she can just feel the faintest bump of the old scar that resides there from his teeth all those years ago. It makes something twinge in her chest.

Koschei sinks two fingers into her, snapping her out of her thoughts as he suckles at her clit, and Theta moans, arching her back, lifting her leg to rest a bare foot on his shoulder as pleasure rolls through her. He presses in a third and then a fourth as Theta keens and takes it all, and pushes up deep inside her, curling his fingers back and rubbing against a spot that makes her vision go white. The orgasm is fast and intense, sending her fluttering madly around him, her thighs shaking and damp bedsheets clenched tight in her fists. 

“More,” she pants when she’s able to, mouth open and eyes rolling back as Koschei slips his fingers from within her and stands. 

She yelps in surprise when he pushes her legs up high, pressing her knees up to her shoulders and letting her brace her feet on his chest as he guides his cock to her entrance and sinks into her. Theta moans, low and guttural in the back of her throat, Koschei sinking deep into her like this. His knot has already started to swell; he clearly enjoyed their warmup as much as she did, and he presses all the way in, pushing it into her and holding still there as her muscles clench and flutter around him. She squeezes him inside her, coaxing him to swell which he does rapidly, both of them gasping at the feeling. 

Koschei’s hands go to her thighs as he starts to rock his hips as much as he can locked inside her, dropping a hand round to splay over her stomach and letting his thumb find her clit, rubbing rapidly. She cries out, her toes curling into Koschei’s shoulders, thighs burning in this position and head spinning as he pushes her body to its limits. She comes fast and hard, shuddering violently, and comes again when he refuses to let up, shrieking into the quiet of her apartment.

He lets her drop her legs down when he’s done, her knees falling to either side of his hips as she feels him continue to come inside her, both of them groaning quietly.

He lifts a hand to her face, brushing back sweaty hair. She must look a wreck.

“You okay?”

Still panting, Theta nods. 

Koschei shifts a bit, bracing himself on the bed on his hands beside her. His arms shake a bit, and she realises the position must be uncomfortable for him.

“Sorry,” she mutters, “do you want to -“

“Can we just -“

They both grunt as they try to move at the same time and his knot tugs at her.

“Fuck, sorry,” Theta mumbles. With some shuffling and muttered apologies she manages to sit up, and Koschei holds her to him as he manoeuvres them up onto the bed and lays down, both of them on their sides and her leg hooked over his hip.

“This okay?”

“Yeah that’s good, thanks,” she says quietly. Silence falls between them. This was the part of knotting that Theta had always thought would be awkward; that half-hour or so after you’ve both finished when you were stuck locked to your partner until his knot went down enough to slip out. Perhaps it would be different with someone she was closer to. Someone she didn’t spend half her life bickering with before they did  _ this.  _ As it goes, she and Koschei haven’t been able to find much to say to each other during these periods of time. 

Koschei lifts a hand and tucks her hair behind her ear, making her flick her eyes up to his in surprise. 

“I like this,” he comments, fingering the ear cuff and chain she wears in one ear. She shifts against him.

“Thanks.” Theta finds herself lifting her own hand to touch her fingertips to his jaw. “I like the beard,” she tells him softly. “It suits you.”

“Thanks.”

They fall quiet, resting together as their bodies cool and their breathing returns to normal. Koschei steadily softens inside her, his knot deflating until he can take hold of her hips and ease his away, sliding out of her. She crawls away once she’s free, up to the pillows to collapse down. Koschei climbs up next to her, flopping down onto his back with a groan. He drags the tangled duvet up over them, and Theta nestles down beneath it. 

They fall quiet. She doesn’t know whether it was the good sex, or a dip in hormones, but Theta feels the lingers of the fury she had felt for Koschei earlier dissipate. Probably, he’d only meant to be reassuring towards her. Perhaps she had blown what he said out of proportion in her head… either way, this heat has been intense and bizarre enough; she doesn’t want to fight with him as well. 

“I’m sorry for earlier,” She says quietly. “In the bathroom.”

Koschei turns his head to look at her curiously and she bites her lip. “I was unfair to you. You were just… our past was a long time ago now. But the memories are still…” she trails off, struggling to explain herself. Koschei is quiet, letting her find the words. “Anyway, it’s the past. This has nothing to do with that.”

“It’s alright,” he says after a long moment, and lifts a hand to fiddle with a strand of her hair. “You were upset, and I didn’t like it.” He scowls, like even the memory is offensive to him, and Theta sighs and rolls onto her side to face him. 

“Just… instincts,” she excuses him. “Chemicals. Biology making sure you care for the Omega you’re mating so she can survive to bear your young, and all that.”

“Hm,” he comments, then his eyes go comically wide. “Shit - Theta - are you -“

“Oh - no it’s okay,” she quickly catches his jist. “My suppressants are birth control. As long as I start taking them once my heat’s over again it’ll be fine.”

“Oh.” He visibly relaxes at that, and Theta hates that tiny voice inside her that’s disappointed, that tells her she wished he  _ wanted  _ her to bear his children. She hates being an Omega. 

“Good,” he says, “that’s good. I really should’ve asked before…”

“We were a little busy,” she shrugs with a small smile.

“Yes I suppose we were,” Koschei chuckles softly. “And - don’t worry. About earlier. This thing…” he blows out a breath. “For both of us, it’s complicated. With what happened before.”

Theta looks down and nods. “I know. I think the memories just kind of…” she waves a hand, and Koschei nods, understanding. 

A silence falls between them, both getting lost in the past. In what happened. What was. What… could have been. 

“I think about it a lot,” he says, and Theta feels her throat grow tight. She wants to clutch him to her, beg him to tell her why he didn’t want her then - why he doesn’t want her now, but she recognises that for what it is, and forces herself to think rationally.

“I think about it too,” she admits, and another quiet falls between them.

“I felt it, you know,” he murmurs lowly after a while, and Theta’s brow furrows.

“Huh?”

“When you -“ he swallows hard, pain in his eyes. “Whatever you did - or took. To break the mating bond. I  _ felt it _ . The moment it happened.”

“...Oh,” she utters, then his words register fully and she frowns deeper.

“Hold on - whatever  _ I  _ did? It - it wasn’t me,” she splutters. She thinks she feels Koschei freeze against her.

“What?”

Theta sits up abruptly in the bed, staring down at him. “Is that what you thought? I didn’t - they gave me something, injected me with something - I didn’t even have a choice, if I did I would never -“

She cuts off her confused rambles when Koschei lurches upright and flies out of bed, startling her when he grabs the nearest item in his reach - her alarm clock - and hurls it with full force into the wall. 

“Koschei -”

The chair over by her little desk in the corner is next, Koschei picking it up and throwing it against the wall, turning and swiping everything off the desk with a yell, slamming his fist down on the surface -

“Koschei, enough!” Theta shouts - and it isn’t how it’s supposed to be - Omegas aren’t supposed to give orders to Alphas, and Alphas certainly aren’t supposed to obey them but - Koschei stops, and turns to face her, breathing hard, eyes wide and wild. 

They stare at each other, the space between them thick with tension. 

“I thought it was you,” he finally utters when he can speak again. He stumbles over and falls to his knees beside her on the bed, takes her hands. “I thought you didn’t want me…”

“Koschei,” Theta’s eyes well with tears. “No - I thought you didn’t want  _ me -  _ you came back and - and it was like you couldn’t even look at me… I thought you - felt like I’d tried to trap you… like I’d made you bite me and you never wanted -“

“ _ No.” _

They stare at each other. A bead of sweat trickles down Koschei’s forehead and Theta’s eyes follow it, continuing down over his face, eyeing his plump lips, parted, thinking of them on her neck while he’s inside her -

She lets out a whimper as a fresh wave of slick rushes from her, and then Koschei is on her, clambering up onto the bed on top of her, pushing her down and kissing her until all she can breathe is  _ him,  _ and she spreads her legs, more than ready for him to take her again when her hands come to rest on his back and she realises that he is shaking. 

“Koschei,” she breathes against his lips. 

“They took you from me,” he growls, voice barely above a whisper but fury dripping from ever syllable. He presses his face into her neck. “They took you, and they -“

“Shhh,” she hushes him, but it has no effect. He shakes harder.

“All these  _ years _ … every damn fucking  _ day!  _ I could have had you - you could have been mine - they -“

Realising his Alpha temper was rising to dangerous levels, Theta turns her head and murmurs his name softly in his ear, stroking his back, tilting her hips up to him and letting her feel her slick for him in the hopes it will calm his rage. Not that she’s afraid for herself - Koschei would never hurt her, but in this state she doesn’t know what else he might do. It was probably best to try and get him back under control before he stormed from her apartment in search of blood and murdered the first man he met on the street. 

Every exhale is a growl rumbled against her skin, breath coming in fast, bellowing puffs against her neck, every muscle of his form tense under her touch as she smooths her hands over his back and murmurs soothingly to him.

“Focus on me… I’m here now, nothing else matters right now,” she breathes, and squirms beneath him. “And I need you… please… your Omega’s in heat and she  _ needs you  _ Alpha…”

She doesn’t even realise she’s called herself his out loud until the sentence has left her lips, but it seems to work. The growls he’s giving quieten and his breathing evens out, his body shifting over hers so his straining cock can slide over her aching cunt. She throws her head back, arching towards him. “Yes.”

“Theta I don’t,” he puffs, “don’t want to hurt you -“

“You won’t,” she murmurs, lifting her hips eagerly. Still he hesitates, trembling over her. 

“I can’t - I feel -“ 

“It’s okay.”

“It’s not. This  _ rage -“ _

“Then give it to me,” she offers. “I can take it. I  _ want it.”  _

Koschei freezes, and looks down at her like she is a wonder. He just stares at her for a long moment, and Theta makes a small sound, rocking her hips uncomfortably beneath him, whining quietly as her Alpha refuses to fill her where she’s so achingly empty, then abruptly - she realises his shaking has stopped.

“It’s you,” is all Koschei says, before he shifts his hips and presses into her, and this time… this time something feels different. He looks into her eyes as he pushes inside her, and Theta almost climaxes right then when she remembers that  _ he wants her _ . He’s always wanted her and she’d been wrong - so wrong and stupid, and he’d been stupid, they’d both been stupid and they’d wasted so much  _ time… _

“Don’t cry sweetheart,” he murmurs, hands on her face, all the anger from before completely dissolved, thumb brushing away a tear she hasn’t even realised was falling, “I’ve got you. I’ve got you now.”

“Koschei,” she breathes, and he drops his head to open his mouth over her neck as he moves inside her. 

“ _ And I’m never letting you go again.” _

Theta  _ does  _ come then, her whole body shuddering and clenching madly around his, gasps spilling from her open mouth as she clutches at his back, pleasure and joy and endorphins rolling through her, making her whole body quiver in delight. 

He fucks her steadily, hard but not forcefully, simply giving both their bodies what they so desperately need. Theta clings to him, locking her legs together at the ankles and digging her nails into his shoulder blades to keep him pulled tight to her, uncaring how his weight presses on her small torso. 

“Bite me.” 

It spills from her lips after her second climax, and Koschei inhales sharply and freezes only momentarily before fucking into her even harder and faster, groaning into her neck.

“Theta - you don’t - don’t know what you’re saying -“

“I do,” she nods, clawing at him, her little nails raking down his back. “I want you - all of you. Wanna be yours. Again. Always been yours… Please Alpha…  _ bite me…” _

“You’re not thinking clearly,” he tries. He stops moving as well, clearly determined to force her to focus on his words. She moans in protest, rocking her hips until he pins them with a strong hand and she huffs, panting. 

“Perhaps I’m not right now,” she agrees, “but I know that every day since the first bond was broken it’s ached inside… that some part of me has always wished it never was.”

His lips part and his eyes glisten as he stares down at her.

“You… really?”

She nods. 

“You really want - ?”

“I want  _ you _ . I want your cock and your knot… and your teeth in me, making me yours forever…  _ please.” _

Koschei’s Alpha is clearly as powerless to resist her Omega than she to beg for what she needs. He pulls out of her, and she whines in protest, but quiets down when she realises he only means to turn her over, pressing her onto her front and pushing her face into the pillows as she lifts her hips for him, eagerly spreading her knees wide and groaning as he shoves back inside her. 

“You’re so good,” he’s panting, smoothing a hand up over her sweating back, tracing the bumps in her spine. “So good for me Omega… my Omega…”

She nods frantically. “Yes - yours. Yours.”

She feels him shift behind her, feels him lean over her, curling his body over hers, going onto his hands and knees so she is pinned, back arched, totally helpless beneath him as he leans down. Like she would want to escape  _ now. _

She feels his breath ghost over the back of her neck first. Then the sweep of his hand as he brushes her hair to one side, then his nose, nudging through it as Theta turns her neck and bares her gland for him, waiting, wanton. 

It throbs and tingles when he swipes his tongue over the sensitive flesh, and she can’t hold back her guttural moan as his hips slap into her backside. She can feel his knot swelling, feel it catching on her on each thrust now, until Koschei  _ shoves,  _ and then he’s in her, and she’s gasping, and moaning, knuckles white in the bedsheets as he swells further inside her. And she feels so full, so unbelievably full and perfect, the only thing she wants -

His teeth close over her neck and sink in. She yelps, her whole body giving a jerk beneath his, her cunt contracting around him hard, and then he’s biting down, bearing down on her, his tongue laving as his saliva sinks into her bloodstream, bonding them forever, and Theta is gasping, and crying, and coming harder than she ever before has in her life. 

She’s fairly certain she blacks out for a moment, because the next thing she’s panting, gasping for air where she lays sprawled on her stomach with Koschei collapsed over her, and he’s soothing the bite he’s given her with his tongue, purring somewhere deep in the back of his throat as he laps at it. His knot is lodged firmly inside her, her muscles clenching and holding him in place as his seed pumps into her steadily, filling her with his cum over and over until she’s so full she’s sure her stomach will swell with it. 

Theta moans, body giving a shudder of utter contentment, her toes curling and warmth and peace and completeness washing through her.

He shifts, rolling them to their sides, both hissing at the change in position with his knot locked inside her. His arms encircle her, and he can’t seem to leave her neck alone, kissing and nipping and licking at the sore flesh. Theta’s eyes flutter closed and she hums, arching her neck to give him full access as she lifts an arm up behind her, pushing her hand into his hair and gripping to keep him pulled to her with a happy sigh. Her cunt squeezes him, and impossibly, she feels more of him pump into her. 

“Does it hurt?” Is the first words he rumbles to her, spoken directly to the fresh bite mark, and she smiles. 

“A bit. Not really. Just… hot, and tingly.”

“What about when I bit you?”

“Mmm yes, it hurt,” she sighs, “but I liked it.”

She feels him press a smile into her skin. “My good, brave Omega.”

A little aftershock of pleasure shoots through her at his words, making her gasp, body twitching, and him growl in delight. 

They should talk about this. She knew that. Take advantage of this brief refractory period where they were both lucid enough to form clear thoughts.

“Regrets?” Koschei mumbles after a couple of minutes, and Theta shakes her head.

“Never.”

And that’s all the conversation they need. 

—

**Notes for the Chapter:**

> You may have noticed it's changed from 3 chapters to 4... just an epilogue type chapter to come after this! :) Comments are hugely appreciated as always!! They give me life 🙏🙏❤️


	4. Chapter 4

It’s later that day when her heat and his rut have cooled considerably, enough for her to feel the soreness in her limbs and her cunt at least, even though the full throb of arousal was still there at the edges of her conciseness. It wasn’t a bad feeling, it was the good kind of sore, like muscles well used after a good workout - her body telling her she’d done something right. 

They are resting together face to face on their sides for now, and although his knot is inside her, she doesn’t feel that edge of a buildup is already beginning again in the pit of her belly like usual in these moments. She just feels sated. 

Koschei had fetched something resembling dinner from her kitchen a little while ago (beans on toast and three hard boiled eggs each - for protein - was the best he’d managed) and she lays draped across him, stomach, cunt and spirit full, and Koschei’s arm wrapped around her, his other hand tracing lightly up and down her shoulder.

“I should never have let them take you.”

She shifts to look at him in the dark when he speaks, blinking up at him sleepily. “What?”

“That first time,” he says. Oh. Theta had wondered if they were going to bring that up again. She isn’t sure how she feels about it - too content with _here and now_ to let herself drift back into their painful past. “I should never have let them take you from me. You were _mine,_ \- and they just… I’m sorry. So sorry, my Theta…”

“Koschei,” she murmurs sadly, lifting a hand to his face, “We were children…”

“No,” he argues, “we weren’t. Not after that day.”

Theta knows what he means. The world had shifted that day, and it had never gone back to the same again. It’s only now, that she lays with him again, finally bonded to him once more that she realises it’s the first time it’s felt right since. 

“I’m going to murder all of them.”

“Shh,” Theta soothes at his low growl, rubbing her hand over his back. She squeezes the muscles of her cunt around him inside her, again and again, until he relaxes against her.

“Not fair,” he grumbles docilely as she nuzzles her nose into his neck. She smiles.

She feels his knot go down as he softens inside her a short while later, and shifts her hips, letting him slip from her. A hiss spills from her lips as he does so, and Koschei lifts a hand to her face.

“Are you alright?”

She nods. “Perfect. Just a little sore now - I think that’s good. I think my heat must be ending.”

He leans in, sniffing her, inhaling deeply by her neck. 

“Yeah, I think you’re nearly done. Are you tired? Do you want to shower? Some more food?”

Theta can’t stop the smile on her lips as he fusses over her. She’s always been fiercely independent, having to look after herself practically her whole life and swore she always would but she has to admit - it is nice having Koschei care for her like this. She knows that’s his Alpha instincts. Nature dictating that the Alpha must tend to the Omega’s needs, even in the midst of a full rut, ensuring she remains healthy enough to conceive. She has vague memories of Koschei feeding her bits of fruit and cheese and bread, and making her drink water in between fucking her brains out over the last few days. So while her head tells Theta to tell him she can sort herself out and get out of bed, something deep and primal inside her encourages her to burrow further into the duvet and gaze up at him instead. 

“I am hungry,” she admits. “And tired.”

Koschei looks pleased at the opportunity to provide for her needs, and leans down to kiss her quickly before throwing the covers back and climbing out of bed. 

“Take a nap,” he suggests, “I’ll make us some dinner.” He considers. “Or maybe just… order some food in since I think we’ve cleaned out your fridge over the last few days.”

“Hmm, I wasn’t exactly prepared for this,” she remembers.

“What do you want to eat?” He asks as he pulls on his boxers and grabs for his shirt.

Theta nestles further into the warm bed, already feeling her eyes dropping. “Mmm don’t mind,” she mumbles, closing her eyes, pleased of the opportunity to cater to his instincts further; “You decide Alpha.”

She can _feel_ Koschei’s delight as he tucks the duvet up around her before he leaves, and Theta nestles into the soft warm bed, her inner Omega humming with contentment at her Alpha taking care of her. And maybe her real self too, just a little bit. 

—

It’s Friday by the time they both feel fully back to normal, and Theta is glad she has the weekend to fully recover from her heat before having to go back into work and face the storm she and Koschei have coming. Not that there’s much ‘recovering’ to do… before, her heats have always left her feeling wrung out and exhausted, like getting her strength back after a nasty bout of the flu but this one… if anything, Theta feels even more energised than usual. Her skin glows, her hair is shiny and her body feels healthy and fulfilled. She supposes that _this_ is the reason most Omegas choose to find an Alpha to ‘help them through’ their heats, even if they aren’t in a committed relationship with one. 

Despite the fact that it’s over, Koschei stays the weekend without asking. He does pop home to get some of his things, and Theta had felt so panicked at the thought of him leaving, even for an hour, that she goes along in the car with him. Perhaps it’s always like this with new mating bonds, or perhaps it’s because she was ripped painfully from the last that she feels anxious at the thought of being away from him for even a minute. By the way Koschei grabs her face and kisses her hungrily the second he slips back into the car beside her, she guesses he at least feels the same way. 

They get pizza, and put on a sci-fi show on netflix on friday night, curling up together on the sofa and picking apart everything in the show that doesn’t make sense. 

“She reminds me of you,” Koschei comments around a mouthful of pizza. 

“Who?”

“The main character.”

Theta snorts. “The villain reminds me of you.”

Koschei elbows her with a glare and she laughs brightly, snagging a bit of mushroom off the top of his slice pizza. 

“Hey!”

“I like mushrooms,” she pouts, “there wasn’t many on my half.”

Koschei rolls his eyes and goes back to his food, but a minute later, he piles a handful of them onto her slice that he’d picked off his own, and Theta is so touched she feels something warm bubble inside her chest.

On Saturday they spend the day doing much the same; watching telly, eating food to make up for all the calories burnt over the last few days, and just talking. They’ve hardly spoken in Theta’s year at Gallifrey, and she and Koschei have a lot to catch up on in between now and the last time they’d seen each other when they were still in school. It’s easy with him, and Theta is glad that now they’re not so concerned with fucking each other that they can still get along as well as they used to. 

On Sunday morning she wakes up to a warmth between her thighs, and groans as her consciousness registers the feel of a hot tongue sliding between her legs. She buries her hands in Koschei’s hair and closes her eyes, content to stay here where she’s warm and comfortable and Koschei’s to do as he pleases forever as far as she’s concerned.

It’s slow and lazy, and the orgasm isn’t earth shattering when it comes but warm, beautifully, wonderfully warm, just like the heat of Koschei’s body when he settles fully over her. She slips a hand down between them to squeeze him, finding him hard and ready.

“No knot this time,” he mumbles like an apology, and Theta smiles.

“It’s okay,” she says, stroking him as she spreads her legs. “I don’t need your knot; I just need you.”

“Not what you were saying a couple of days ago,” he quips with a teasing smirk, and Theta squeezes him hard in retaliation, before lining him up with her entrance and moving her hand to his hip as he slides home.

He buries his face in her neck and mouths at her new mating bite as he moves within her, seemingly unable to stop himself. She’s bleeding a little again by the time he’s done but she can’t find it within herself to care.

“Tomorrow,” Koschei sighs as they get their breath back, and Theta knows what he’s thinking about - she’s been trying not to, herself.

“Yeah,” she sighs back, and as his hand finds hers and squeezes, she feels that whatever happens at work tomorrow, it’s going to be okay. 

—

They walk into Gallifrey together on Monday hand in hand. There’s absolutely no point in pretences, since everyone in the building would be able to scent them on each other the second they appear anyway. Theta had pinned her hair up, scraping her short blonde bob that usually covered the old scar on her neck into a ponytail, exposing the fresh mating bite proudly. It was easier than having to explain anything with words. 

She’s still nervous as hell as they get to their floor, her hand sweating in Koschei’s as he walks her to her desk, trying to ignore the strunned stares and whispers. He squeezes her hand once before he releases it, pulling out her chair for her and leaning down to kiss her when she sits, one large hand on her face, claiming her for all to see, just in case the mark and the fact that she positively reeked of him hadn’t already taken care of it. His lips break from hers and he nuzzles her neck possessively, a quiet purr in the back of his throat before he stands straight and pulls away. Theta’s face is red as he walks away to his office, but it’s a pleasant sort of flush as she logs into her computer and tries to ignore the open-mouthed stares. 

It’s only an hour before they are called up to the top floor to see the CEO. 

Koschei takes her hand in the elevator and doesn’t let it go, even when they’re called into the large office and bid to sit down in front of a gathering of the ‘higher-ups’. 

As it turns out, things are okay. Koschei is her department manager and she’s his mate now, which means she’s protected. The laws were stupid, but in this case, they worked in her advantage. Lying about designation was a sackable offence at Gallifrey, but the law strictly prevented all organisations from firing employees because they had mated. Everyone knew that the biological pull that drove two people to do so was too deep and strong to be interfered with. In this case the law overrode company policy. And anyway. Despite a severe berating for lying in the first place, the company director hadn’t seemed too mad about having to keep her on. She was one of the best young scientists at the company - she knew that. He knew that. They’d be hard pushed to replace her. And even though they knew now that she was an Omega, Theta had spent a year proving that it didn’t interfere with her or anyone else’s work. And now she was mated to Koschei, her scent would be of no interest to any other Alpha in the building anyway. 

“Sooo,” her co-worker, a young Alpha named Ryan says when she gets back to her desk, feeling a lot lighter than when she’d left it. He leans in. “An Omega, huh?” 

A low growl comes from Koschei, still standing behind her, and the other Alpha immediately raises his hands. “I’m just curious, is all. I know she’s yours.”

“Koschei.” Theta gives him a look that tells him to back off. “I’ll see you at lunch, okay?”

He looks between them with narrowed eyes for a moment, before clearly gauging that this young Alpha was no threat to his mate, and nods in resignation before walking away. 

Ryan watches him go before turning to her. “Alright. The whole Omega thing is mad enough but _Koschei!?_ How long’s that been going on? I thought you hated him. You two are _good_ , man.”

Theta chuckles. “It hasn’t - I mean. We haven’t been dating in secret or anything. It’s… new.”

“New?” Ryan’s eyebrows shoot up. “And he’s claimed you already?”

Theta smiles. “It’s complicated.” She doesn’t feel like divulging their history to Ryan today, but maybe sometime she would tell her friends about their past. 

A new IM flashes up in the corner of her screen as Ryan turns back to his desk with a shrug, and Theta’s cheeks flush read when she reads it.

**Koschei: I need to see you in my office during lunch break Doctor. Something’s come up I’ll need you to see to personally.**

A shiver of heat goes through her, and she starts typing that she’ll ‘see him then and does he really think he’s being subtle?’ When she changes her mind, deletes the words, and types just two instead. 

**Theta: Yes boss.**

**Koschei: Make that before lunch. The situation is rather urgent.**

**Theta: No problem, I’m sure I can handle the issue.**

She types her reply with her tongue between her teeth and a poorly hidden smirk on her lips, then quickly sends another message:

**Theta: No matter how hard it is.**

**Koschei: Get in here now.**

She grabs for a bunch of random papers on her desk before getting to her feet, not that the pretence is likely to be convincing to anyone in the office as she makes hastily for Koschei’s door. 

Theta can’t find it within herself to care, not today. She’ll work through lunch to make up for the lost time - it’s not like her boss was going to be on her case, after all.

—

_One year later…_

_—_

The lift pings for her department floor, and Theta smooths hands that are still trembling with the buzz of excitement over her lab coat. She steps out and makes a beeline straight for Koschei’s door, nothing else on her mind but telling him her news before she does absolutely _anything_ else.

When she steps inside his office and closes the door, she can’t keep the grin off her face.

Koschei looks up, and meets it with his own. “Congratulations,” he smiles.

She gasps. “You knew!?”

He nods, tossing his pen down and leaning back in his chair. “I was in the meeting last week. They didn’t let me have a say of course, but it was unanimous anyway. Everyone knows you’re the smartest here.”

Theta feels a pleased flush at his words, both her inner Omega and her true self delighted with his praise. 

“It’ll be longer hours,” she says, “and I’m moving down to the lab permanently.” 

“Of course you are,” Koschei nods, “can’t run it from up here, can you?”

She bites her lip against a grin. “And we’ll still see each other after work. And the weekends. And maybe if our schedules line up we can get lunch some days…”

“It’ll be fine,” Koschei assures her, still smiling for her.

She crosses the office to him, coming to stand between his legs when he pushes away from the desk, draping her arms over his neck as his own smooth up her thighs. He leans in, breathing in her scent, and his hands reach her arse where he squeezes. 

“I’m gonna miss bending you over this desk on our lunch break though.”

She gasps. “That was only a couple of times.”

“Eighteen times,” he counters, “and it has the scratch marks to prove it.”

She smacks his chest lightly, then pulls out of his arms. He looks disappointed, before she crosses the room again and turns the lock on the door. His face lights up when she spins back to face him with a smirk.

“Want to make a few more?”

\--

**Notes for the Chapter:**

> The end! I actually wrote a happy ending for once, I know 😱😂 I hope you enjoyed this slightly strange fic if you’ve read, I’m really glad there’s a least a few of you who’ve told me you were new to the omegaverse thing but gave it a go anyway! Please leave me a comment and let me know if you liked it! ❤️


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